Variable speed device



Nov. 25, 1941. 0, JENSEN VARIABLE SPEED DEVICE Original Filed Jan 21, 1939 2 Shee'lis-Sheel. l I

, INVENT OR. OJQJ/Zs'e/Z ATroRNEm.

Nov. 25,1941. 0. JENSEN VARIABLE SPEED DEVICE Original Filed Jan. 21 1939 2 Sheets-Sheet 2 1N VENT OR. 0/9 J/zs'ez ATTORNEY/3:

Patented Nov. 25, 1941 UlTED STATES P TENT OFFICE 252,078. Divided and this application September 13, 1939, Serial No. 294,598

1 Claim.

This invention relates in general to variable speed devices, and more particularly to variable speed devices composed of sheet metal or any other suitable material. This application is a division of my co-pending application, Serial No. 252,078, flied January 21, 1939.

A principal object of the invention is the provision of a wheel having opposed, recessed, sloping side surfaces which converge at the outer periphery of the wheels, so that two or more such wheels may be co-axially mounted to enable the same to be moved axially into and out of interengaging or nested relationship relative to each other.

A further important object of the invention is the provision in such a variable speed device of novel hub mechanism which functions not only to mount the wheels in desired manner on a shaft, or the like, but also to rigidly retain the inner portion of the sheet metal part of the wheel in place.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

In the drawings,

Figure l is an end elevational view of a driving unit comprising a plurality of wheels embodying the features of the instant invention mounted in sliding relationship to each other upon a shaft which is shown in section;

Figure 2 is a vertical section of the unit of Fig. 1 taken longitudinally of the shaft, and illustrating the relative movement of the wheels in dotted outline;

Figure 3 is a plan view of a sheet metal blank used in making one of the wheels of the unit of Figs. 1 and 2;

Figure 4 is a plan view of the blank of Fig. 3 after it has been bent to form the body portion of a wheel;

Figure 5 is an exploded plan view of the two members comprising the hub portion of a wheel; and

Figure 6 is an end elevational View of one of the hub members taken substantially on the line 65 of Fig. 5.

Referring more particularly to Figs. 1 and 2 of the drawings, reference numeral H indicates in general a variable speed device which comprises a plurality of wheel members, each indicated generally by reference numeral l2. Each of the wheel members 12 is made up of a main portion l3 and a pair of hub members M. The main portion I3 is formed in a manner to be later more fully described from a sheet of any suitable material, such as sheet metal or the like, to provide a plurality of substantially segment-shaped lateral bearing surfaces [5 and IS. The outer ends of the segmental portions 15 and I6 terminate in the same plane, and from this plane, the portions I5 and I6 slope or extend outwardly on opposite sides to provide two opposed bearing surfaces. Each; bearing surface I5 is directly connected to its adjacent bearing surface I6 by a triangularly shaped web portion H which is disposed at a slightly obtuse angle to the planes of each of the two bearing surfaces I5 and I6.

In this manner, a pair of opposed bearing surfaces are provided by the main portion l3 of each wheel l2 which converge at their outer ends and are each made up of a plurality of substantially segment-shaped portions spaced from each other by substantially segment-shaped recesses which substantially coincide with, and are slightly larger than, the segment-shaped portions of the opposed bearing surface.

The hub members [4 are securedto the inner ends of the web portions H in a manner to be later more fully described, and are each provided with a bore or centrally disposed aperture l8. The several wheels I2 of the unit ll (shown as three in number in Fig. 2), are each mounted upon a cross shaft I9, the two outer wheels being slidably mounted thereon, while the center wheel has its hub members 14 rigidly secured to the shaft [9. The hub members IA of each of the wheels [2 are also provided with a plu-- rality of circumferentially spaced apertures 2l through which a series of rods 22 extend .(Fig, 2). Each rod 22 is rigidly secured in any suitable manner to the hub members M of the outer two wheels [2. The apertures 25 in the hub members M of the central wheel l2 are slightly larger than those of the other hub members, so that the rods 22 are readily slidable through the apertures 2! of the central wheel l2. With this arrangement, the two outer wheels l2 may be moved longitudinally of the'shaft I?) as a unit relative to the central wheel I2; I

In such relative movement between the several wheel members, the bearing segment portions [5 or N5 of one wheel Will be moved into and out of the recesses in the adjacent bearing surface of the adjacentwheel to form a variable speed device or adjustable pulley. To facilitate such intermeshing or nesting of adjacent Wheels I2, the hub member l4 of each wheel is made much narrower than the base part of the main portion I3 of the wheel, as shown in Fig. 2. Thus the adjacent wheels I2 may be moved toward each other an appreciable distance, or until the hub members I4 thereof come into contact with each other.

The shaft I9 may be mounted in any suitable manner, but it is preferred that it be rotatably journaled in bearing portions 23 provided at the upper ends of levers or brackets 24, as shown in Fig. 2. In order to prevent longitudinal movement of the shaft I9, any suitable means, such as collars 25, may be secured to the outer ends of the shaft IS. The two bracket members 24 are preferably mounted so as to be swingable together as a unit to move the shaft I9 crosswise thereof, or forward and backward viewing Fig. 2.

The unit II above-described is adapted to be used as a change speed gear mechanism. In such use, a belt 26 of any suitable material and having a trapezoidal cross sectional shape is mounted between the left hand (Fig. 2) and central wheels I2, and extends therefrom around a suitable driving member. A similar belt 21 is positioned between the right hand (Fig. 2) and central wheels I2, and around a suitable driven member (not shown).

With this arrangement and the mounting of the shaft I9 as above described, forward movement, viewing Fig. 2, (movement to the left in Fig. 1), of the shaft I9 will result in increasing the effective length of the belt 2'! in the same proportionate amount. If such movement be imparted to the shaft I9, through the agency of the rockable bracket 24, while the belt 26 is moving to impart motion to the unit II and belt 21, the two outer wheels I2 will be moved to the right, viewing Fig. 2, relative to the central wheel I2 to decrease the distance between the left wheel and the central wheel and to increase the distance between the central wheel and the right wheel. This will result in the driven belt 21 being actuated at a decreased linear speed relative to that at which it had previously been driven.

Conversely, rearward movement of the shaft I9, viewing Fig. 2,- or movement thereof to the right, viewing Fig. 1, will result in the distance between the left wheel I2 and the central wheel I2 being increased with a corresponding decrease in the distance between the central wheel and the right wheel I2, as shown by dotted outlines in Fig. 2. This will function to increase the linear speed of the driven belt 21. It will thus be seen that any swinging movement which is imparted to the shaft I9 by the brackets 24 will result in a change of driving ratio between the belts 26 and 21.

If it is desired to retain the outer wheels I2 in any predetermined or set position on the shaft I9 relative to the central wheel I2, a pair of collar members 38 may be slidably mounted on the shaft. Each of the collars 38 may be provided with a set screw 39 which is adapted to retain the same in set position. It will be understood, of course, that in the operation of the unit II as above described, the collars 38 will not be used.

The outstanding advantage of the unit II above described is to be found in the fact that the wheels I2 are so constructed as to facilitate a relatively wide range of movement between the outer wheels and the central wheel. This highly desirable condition is made possible only by the fact that the wheels I2 are so constructed as to permit very close intermeshing or nesting together thereof. Such construction is obtained by making the main portion I3 of the wheels I2 from relatively thin sheet metal. For example, if these main portions I3 of the wheels I2 were made from cast metal, it would be impossible to so construct them as to permit any appreciable intermeshing thereof, where it is desired that such intermeshing take place on both sides of any given wheel (such as the central wheel I2 in Fig. 2).

Consequently, the particular construction of each of the wheels I2 herein disclosed is of primary importance. For this reason, the method of making the wheels I2 is considered to be an outstanding feature of the instant invention. The preferred method of making one of the wheels I2 is as follows:

The main portion I3 of the wheel I2 is preferably bent or formed from an annular blank of sheet metal 28 (Fig. 3) in one continuous step or operation. The inner diameter of the blank 28 is equal to the outer diameter of the finish portion I3 of the wheel I2. The blank 28 is bent along the broken lines shown in Fig. 3 and inwardly upon itself, so that the outer periphery of the blank comprises the inner edges of the several segment-shaped bearing portions I5 and I6 and the web portions H of the main portion I 3 of the wheel in its final form.

To more fully explain this bending step, the inner periphery of the blank 23 is designated by reference numeral 29. In Fig. 4, which shows the blank after the bending operation has been performed thereon, it will be seen that the edge portion 23 thereof now constitutes the outer periphery. The inner edge of the main portion I3 of the wheel, after this bending operation has been performed, is corrugated, viewing Fig. 4, and is divided successively into a plurality of series or groups of edge portions, each comprising a relatively short edge portion 3I, a relatively long edge portion 32, an edge portion 33 of substantially the same length as the portion 3I, and an edge portion 34 of substantially the same length as the portion 32. In the final form of the main part I 3 of the wheel t2, the edge portions 3| constitute the inner ends of the segment-shaped bearing portions I5, while the edge portions 33 constitute the inner ends of the bearing portions I6 forming the opposite bearing surface of the wheel. Similarly, the edge portions 32 and 34 constitute the inner ends of the segment-shaped webs II. These edge portions 3| to 34 are shown in Fig. 3 as making up the outer periphery 35 of the blank 28.

It will now be better appreciated that the broken lines shown on the blank 28 in Fig. 3 are the lines upon which the blank is folded or bent in the forming of the main portion I3 of the wheels I2. To further aid in visualizing this bending operation, the several portions of the blank 28 which eventually go into the making up of the separate segment-shaped portions of the final product are indicated by the corresponding reference numerals I5, I6, and I! in Fig. 3. Due to the natural resiliency of the sheet metal forming the blank 28, in its final form, as shown in Fig. 4, after the bending operation above described has been performed, the inner portion thereof will be flexed to one side or the other of the outer periphery 29.

The hub members I4 thus perform the two functions of retaining the inner part of the main portion I3 centrally disposed relative to the outer periphery 29, and of providing convenient means for mounting the wheel l2 in any desired manner. Referring more particularly to Figs. and 6, it will be seen that each of the hub portions [4 is similar to the other, and that each comprises a web portion 36 which terminates at its outer periphery in a plurality of circumferentially spaced lugs 31. Each of the lugs 31 extends laterally beyond one face of the web portion 36, and the radial side surfaces thereof slope or taper in such direction, so that the protruding end of the lug is narrower than the other end. The spacing between adjacent lugs 31 is such that, when the two associated hub members M are moved together from their position of Fig. 5 to their assembled position of Fig. 2, the lugs 31 of the two hub members will intermesh, with spaces being provided therebetween of substantially the same width as the thickness of metal used to form the main portion I3 of the wheel.

Thus, to assemble the two members l4 and the main portion l3 of the wheel, the inner part of the portion I3 is sprung inwardly from its position of Fig. 4 to its central position of Fig. 2, and the two hubmembers I4 are engaged therewith from opposite sides thereof. It will be noted from Fig. 2 that the outer diameter of the web portion 36 of the hub members I4 is slightly less than the inner diameter of the main portion l3. In this assembled position, the inner edges 32, 34 of the segment-shaped web portions I! are clamped between the adjacent radial surfaces of the lugs 31. The parts may be retained in this assembled position in any suitable manner, such as by upsetting the edge portions of the outer surfaces of the lugs 31, or welding the hub members M to the segment-shaped webs ll of the main portion l3. It will be noted in Fig. 6 that the web portion 36 of the hub member I4 is that part of the member in which the bore I8 and the apertures 2| are formed.

The method of making the wheels l2 above described permits of sheet metal being used for the main part l3 of the wheel without any undue strains or stress being set up in the metal during the bending operation to which it is subjected.

At the same time, the hub members It function to rigidly retain the main part l3 of the wheel in final shape, while providing an excellent bearing means for mounting the wheel in any desired manner. It will be appreciated that the use of sheet metal in forming the main part l3 of the wheel 12 permits of many uses of the wheel to which it would not be put if it were formed by a casting operation. The resulting light weight of the structure also has material advantages which are not enjoyed by a cast pulley.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the devices mentioned herein and in the steps and their order of accomplishment of the process described, without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms and processes hereinbefore described being merely a preferred embodiment thereof.

I claim:

In a variable speed device, a pair of pulley sections, each section comprising a main part of sheet metal formed to provide opposed, sloping bearing surfaces converging at the outer periphery thereof, each of said surfaces comprising alternate bearing portions and recesses, with the recesses of each surface substantially coinciding with and slightly larger, in the plane of the periphery, than the bearing portions of the other surface, and web portions formed integrally with and joining adjacent bearing portions of said opposed surfaces, and a separate hub portion, comprising a pair of similar members each having a radially extending web portion terminating at its outer periphery in a plurality of laterally extending, circumferentially spaced lugs, said lugs being interengaged with each other and engaging the web portions of said main part therebetween, to rigidly secure the latter and said hub portion together.

OLE JENSEN. 

